Alkylation



Patented Jan. v15, 1946 UN lTiED].

wears PATENT OFFICE arzmnrron.

Carleton :Ellis; Montcljair, N; J., minor to Stand- .ard OilDevelopmentGompany, a e-corporation v I of Delaware:

Noni-swing] Application July swarm-345,854

. comm-.1.- -(cl. 260-6834) This invention relates to alkylation -productst, and process of making same, and relates =-;espe-= cially to the formation of isoparaiilnsirom-an,

open chain olefin hydrocarbon-and-a teirtiurilgf hydrocarbon saturate.v 1 It also inyolves' theinter action of such'unsaturated'and-.saturatedkhydroe;

carbons in the presence of activating-'suliuricacid containing an alkylation promoting.agent.

Interaction of olefinic hydrocarbons-anditera tiary hydrocarbon saturates in --the=:pr.esence:.of activating-sulfuric acid is inhibited-"bye. nu n ber of substances.- *These' inhibitors include 'com- 1" "pounds of membersof group VB, of the;-preriodi c table, e. g., arsenic compounds, andalsomembers of group IIIB of the periodic table, 'suchasialu-fl minum or compounds of boron; Therefore; --I',

prefer-to use sulfuric acid which issubstantiallytertiary hydrocarbon saturates with open chain olefins in" the presenceo'f activating sulfuric acid. Onthe other hand, two ormore of the promo- 'torial agents, if desired, r'nay be employed simultaneously'or in'any mannersuitable to the par- 'ticula'r set of reactants, temperature, pressure,

[and other variables. --The use of elements of group'VIBpf the periodic table as alkylation promoting agentsis disclosed and claimed'in co free from compoundssuch as'those mentionedhf above. Also, I prefer to carry 'out.-alkylation operationsin vessels which are made of mate named substances, upon alkylation operations' is observed whether the activator poison is present inits elemental form, as, for example, aluminum,

or in a compound such as boric acid.

Alkyl sulfates, boththe acid derivative-and those of a dibasic character, for example,rdiiso-. propyl sulfate, likewise tend to retard or repress the alkylation reaction. The organic sulfates 20f.- rials substantially devoid of inhibiting substances. Apparently the inhibiting action 'ofhthe above .pending divisional applicatlonSerial No. 450,620,

filed 'July 11, 1942. Other alkylation-promoting with open chain oleflnic' hydrocarbons in the presence of activating sulfuric acid. Examples of suchpromoting agents include the salts of condensation'products of hydroxy or halogenated 1 ethanesulfonic acids .with amides or substituted, amides of 'fattyacids or the salts of amides or 26 substituted amides of fatty acids alone.

whichexhibit an inhibiting eflect on alkylation are those in which the hydrocarbon chain is relatively short, as for example, of the order 013; 4, 5 carbon atoms or thereabout. Alkyl" hydrogen sulfates and vdialkyl sulfates may beformed during the alkylation step by union of sulfuric acid with the olefin hydrocarbon charging stock. However. the inhibiting effect or such sulfate compounds is overcome apparently to a substantial degree, according to my invention, by certain agents which promote the -alkylation reaction, 1. e., combination or olefin and paraffin. I' do not *wish to "infer that the valkylation-promoting agents herein disclosed completely suppress formation of alkyl hydrogen sulfates and diaikyl sulfates' On the other hand, I do find that certain agents promote the alkylation reaction, thereby overcoming to marked extent the inhibiting eflect of the alkyl hydrogen sulfatesand dialkylsulfates.

'Alkylation-promoting agents; according to my invention, include the elements of group-VIE of theperiodic table, e. 8-, suliun-selenium, ortellurium. These elements may be employed-individually as prom'otorial .agentsior alkylation of Another type'ol wetting agent which may be used as alkylation 'promoting agent according to my inventionis asaltof the sulfuric acid ester or aliphatic alcohols, such as sodium lauryl sulfate. Instead of sodium lauryl sulfate, other alts of alkyl sulfates may be used. Also, if desired,

a combination of salts of various alkyl sulfates may be'utilized as alkylation-promoting agents. The alkyl group of the wetting agent described I; abovemay be either saturated or unsaturated. Further, the hydrocarbon chain of the salts of 1 alkyl sulfates preferably contains about 10 to 14 1 carbon atoms, or thereabouts.

It was pointed out previously that alkyl sul,v I 9 fates and alkyl acid sulfates in which-the hydrof." carbon chains were of the order of 3, 4, or 5 carbon atoms, or thereabouts, exhibited an inhibiting eilect on falkylation of tertiary hydrocarbon saturates with oleflns in the presence of activating sulfuric acid. However, it has been observed that alkyl sulfates containing, say, l0, 12 or l4' carbon atoms per molecule not only failed to exhibit an inhibiting effect, but on the other hand, acted as alkylation-promoting agents for my purpose. I In other words, high molecular weight esters of sulfuric acid appear to exhibit an eflect (i. e., promoting) which is just the reverse of that (i. e., inhibiting) shown by low molecular weight esters of the same type;

Oleilnic hydrocarbons, such as isobutylene, di-

may be employed in.

strength were placed in a reaction flask together with the substances being tested as accelerating or repressing agents, and the whole mixture cooled to about -15 C. Liquid isobutane amounting to 460 g. was added to the mixture and the composition stirred for a few minutes. Then 92 parts of diisobutylene having a boiling range from 102-105 C. were incorporated drop- I wise with vigorous agitation over a period of Intimate contact of the hydrocarbon reactants with each other and with the activating sulfuric acid containing an alkylation-promoting agent aids both the completeness and degree of alkylation. Preferably, therefore, the reactants are kept in the liquid. phase. This may be effected by lowering the temperature of reaction or by increasing the pressure, or both. In this way hydrocarbon reactants which. are gases at atmospheric temperatures and pressures, to. g., isobutane, n-butylene, isobutylene and the like, may be maintained in the liquid phase while in contact with theactivating sulfuric acid containing an alkyiation-promoting agent and with each other. However, it is not necessary to maintain all reactants in the liquid phase. In some cases it may be desired to conduct alkylation operations ,with one hydrocarbon component in the. liquid phase, and the other hydrocarbon component in the vapor phase. Forexample, a saturated hydrocarbon containing a tertiary carbon atom may be agitated with sulfuric acid containing an alkylation -promoting agent at a' temperature and pressure at which the hydrocarbon will remain I substantially in the liquid state. The gaseous olefin hydrocarbon then may be conducted in'a slow stream through the mixture of activating sulfuric acid containing an alkylation-promoting agent and tertiary hydrocarbon saturate. Also, both tertiary hydrocarbon saturate and olefin may be maintained in the gaseousphase during alkylation. As an alternative procedure, the two reactants may be admixed in the gaseous phase and allowed to stream through an alkyla- I tion agent such as activating sulfuric acid containing an alkylation-promoting agent. I

Again, a mixture of olefins, suchas one containing propylene andbutylenamay be an appropriate alkylating agent. Similarly, a mixture of two or more tertiary hydrocarbon saturates, e. g., isobutane and isopentane, may be employed if desired. 1 v v I Instead of using, the olefine in its monomeric form, I may employ its dimericor trimeric isomer. The latter many times appear'to give as good results as the monomer and being liquids at ordinary temperatures, are much easier to handle. Thus diisobutylene or triisobutylene oftentimes is a more convenient alkylating agent than isobutylenc. Furthermore, the dimer or trimer seems to react, at leastto avery substantial .degree, in the presence of sulfuric acid containing an'alkylation-promoting agent as if it were the monomer. Thus, diisobutylene and isobutane interact to furnish a very considerable yield of isooctanes and not mainly: dodecanes as might be I expected. In like manner. instead of using a mixture of olefinic hydrocarbons, e. g propylene admixed with butylene, I may employ the co'-polymer resulting from the interaction of such ole- The following mode of procedure indicates the general character of the alkylation operation. In each experiment 920 g. of sulfuric acid of 98% about 120 minutes. During the addition of the olefin the temperature of the bath surrounding the reaction flask was maintained at --16" to --14 C. When the addition of the diisobutylene was completed, the mass was stirred for twenty minutes and then allowed to warm slowly to room temperature.

The reaction products were transferred to a separatory device and the acid layer withdrawn. The hydrocarbon layer was washed with water, dilute aqueous solution of sodium carbonate and then again with water and finally dried over anhydrous sndium sulfate. The dried hydrocarbon layer was stripped of any unreacted isobutane which might be present, and afterwards subjected to fractional distillation, the portion boiling within the range of 100-130, C. being taken as the octane fraction.

Data given inthe following table illustrate the inhibiting influence of a number of substances on the alkylation of isobutane with diisobutylene.

.Sincethe endeavor was made to obtain a good yield of octane stock. some emphasis is placed upon the production of this material. Alkylation-inhibiting substances include arsenious acid, boric -acid, aluminum, and diisopropyl sulfate. The results included in Table I below indicate the repressing or inhibiting action of these agents both on the total yield of reaction products and on the yield of octanes'.

Table I Arseni- Boric Alumi- Duso' Inhibit ng agent Blank ous mm mm 1mm S55E22 Per cent by wtroi I added compound.. (l. 5 l0 1 D. 5

Total yield of reaction products I grums 136. 2 118. 2 90.1 115. 5 105. 4

Fraction boiling up to C -grams. 2i. 6 i7. 3 6. 6 15.1 12. 4 Fraction boiling I from 100-13 0.

grams.. 1 56.3 45.7 19. 2 41.0 31.6 Fraction boiling I from ISO- C. I

. grams 25. 7 12.8 12.8 20.4 10.8 Fraction boiling a b o v a 175 0.

grams 32. 7 42. 4 51. 5 39. G 50. 6 Yield of octane per cent 30 .24. 4 i0. 2 22 16. 9

It will be noted from a comparison of the total yieldsof reaction products that addition of any of the inhibiting agents disclosedabove caused a decrease in the totalyield of reaction product as compared with that secured when only 98% sulfuric acid (column 1) was used as activating agent- Further, it will be seen that the presence of the inhibiting agents also causes a decrease in the yield of octane stock.

Using the procedure described above for alkylation, a number of substances were found to have alkylation-promoting properties when added to the activating sulfuric acid. These alkylationpromoting agents included selenium, sulfur, aluminum chloride, sodium salts of condensation products of hydroxy or halogenated ethane sul- Table II below indicate the alkylation-promoting action of the agents described above, both on the total yieldof reaction products and. on the yield of octanes.

In some cases the product is characterized by containing traces to minute quantities of sulfuric acid or its compounds. In 'other instances when it is formed in the presence of substantially poison-free sulfuric acid, the product likewise will be substantially poison-free. When elemental sulfur is the alkylati'on-promoting' agent, however, it was found that a very small proportion of this element was present in the product. As a consequence, distillation of the hydrocarbon material (resulting from the interaction of, say, di-

Table II Aklylation-promoting Blank Selenium Sul- 332 Igepon I Gardinol chloride P Per cent by wt. of add- I edcom ound l v 2 7 0.2 1 Total yie d oi reaction products.... '.grems.. 136.2 140.7 145.1 127.9 130.9 123.8 Fraction boiling up to 100 C-- .grams. 21.5 27.5 32.1 28.9 24.9 28.7 Fraction boiling from 100-13 grams. 56.3 67.8 62.6 63.2 63.7 r .601 Fraction boiling from 130-175 C. -,-grams 25.7 18.5 23.9 v 13.6 17.5 13.3

Fraction boiling above r 175 C "grams; 32.7 28.2 26.5 22.2 24.8 21.7

Yield of octane stock I I I per cent. 36 33. 2 34 34 32 Table III Alkylation-promotlng agent Blank Sulfur Blank Sulfur Per cent by Wt. of added compound 2 2 Temperature of reaction, C..... -25 -25 -30 30 Total yield of reaction products 40 grams.. 135. 9 119. 3 122. 0 105. 6 Fraction boiling up to 100 0 grams.. 29. 0 22. 2 22. 2 l6. 8 Fraction boiling from 100 to 130 C .grams 43. 9 49. 9 37. 2 40. 9 Fraction boiling from 130 to 175 0 .grams 20.4 11.0 20.5 11.1 Fraction boiling above 175 C grams. 42.6 36. 2 42.1 36. 2 Yield of octane stock per cent.. 23 27 20 22 bon having a tertiary carbon atom) in the presence of activating sulfuric acid containing .an alkylation-promoting agent such as those here- -,inbefore described. However, the alkylation operation is directed more particularly to the production of octane material by the process comprising essentially the interaction'of a butene and isobutane in the presence of activating sulfuric acid containing an alkylation-promoting agent.

isobutyiene and isobutane) may yield some fractions, particularly those of the higher boilin ranges, containing sulfur and/or its derivatives. e. g., hydrogen sulfide or mercaptans.

This condition, i. e., presence of sulfur or its derivatives, may be eliminated or at least to a large degree pallia'ted, if desired, by subjecting the alkylation product to some refining treatment prior to distillation. Thus, the hydrocarbon material may be washed with an aqueous solution of analk'ali sulfide (e. g., sodium sulfide), the latter uniting with elemental sulfur to form an oil-insoluble but water-soluble alkali polysulfide. Another modification comprises filtration of the liquid hydrocarbons through a bed of solid alkali or alkaline-earth sulfide whereby extraction of elemental sulfur may be accomplished. Still another procedure includes distillation of the entire product, or a portion thereof, say, the octane fraction and higher, under reduced pressure.

Alkylation-promoting agents suitable for my purpose, however, are not and should not be limited to those specifically described in the examples hereinbefore given. In addition to the substances mentioned, tellurium may be used as.

alkylation-promoting agent, as well as salts of a sulfonated or sulfated aliphatic hydrocarbon. The latter may be saturated or unsaturated, and maycontain elements other than carbon and hydrogen in the aliphatic chain, as, for example, oxygen, nitrogen or sulfur. Any one of the latter elements or any one pair or all of them may be present in the aliphatic chain. Also, any combination of two or more of the alkylationpromoting agents disclosed herein may be employed.

It is, of course, in the light of the present disclosure, now feasible to make various modifications in the alklation operation wh'ch has been illustrated and described above. Although the reaction as described is brought about at atmospheric pressure, it is quite possible to use higher or lower pressures. When the higher pressure is used, a pressure vessel may be employed which permits raising of the temperature from that below 0 0., as illustrated here. to as high as 50 or 60' C., or higher, and thus bring the reacting 4 2,368,159 mixture to a warm or even mg condition. me-it s example, the sodium salts thereof.

conditions in the presence oi" sulfuric acid of upon interaction takes;pieces-cil a:,1me1fe1'eedily r aikyla-tingconcentrationgsaidxcidicontainingan when activator -pois oningsubtan95areEnot-ipreallwlation-promoting; zagent selected i'rom :1 .the Sent. 4 52 when he r ee entsme in: a-riwsrm smupiof."w ttlneiasentsiconsistinwrihlsh molecor even-a hoticonditiom -interactiontakes place 5 inlarswweightv reNascyl=itaurines; and-sulfuric iacid even morezreadi l whensn ablation-promoting ester's .0! zhigh-.;molecular1 meightialiphaticrmonoagentispresent. I u 4 'jhydliicalcoholsarx I 1 3 since themateria do at sea: .-;:Aiprocess-whichscompriscs lsopsrmgner swper p rsggsccn 32o: the {emilamnqwithioleiinvunderialkylation'reactioniconpcrature at yvhich ordinargs alkylationnv is Jrej- 10 ditionsingthe presenceoisuliuricncidfoifalkaylatquentiycarried out, it is possible ,thattheresna concentration,zsaidaacid.zcontainingipromobe a critical temperatureatiwhich the promotion tional amounts 01' a high molecular weight N-acyl agents involved are active. This should lie sometaurine. I

where between 70 C. and cold room tempera- 4. A process comprises reacting isoparture. 15 *aflin witholefin under alkylation reactioncondi- Reference in the specification to the variousfl ltion's lifntheprcsericeof sulturicacid ot-alkwlatgroups of the periodic table refers to theMenlug-concentration, said acid containing promodelyeev Periodic Table particularly with respect tionalam'ountsof asulturic acid ester'oi! a'hish to the A and B designations, they are in acmolecular weight aliphatic monohy'drlc aicohol. cordance with the designations and arrangement gof 5'; A process as in claim lgwhereinfthe'diof the elements in The Periodic Series of: 1Ele-' isohutylene isirepiaced by at least one Crmonoments," Table 8, appearing in Meilor's "Modem j solemn. I y T I Inorganic Chemistry," Revised Edition, by G. D. 6. process which comprises-reactin 139 81- Parkes and J. W. Mellor, 1939, published by Longwith monoolefln under alkyla'tioni-reaction mans, Green and Company. conditions in the presence ofzsulfuric acid-pi When used in the specification and claims, the. ,al kylating concentratiom;saidacid'hontaining'an terms "N-acyl taurines" and sulfuric acid esters" 'alkyl ester otlsuliurlc acid, saidester having not i are intended to ilicludethe simple saltsas, for: less' than =10 carbon atoms'per molecule.

7; A'process asin claim 6 wherein the sulfuric an acid ester 'is a -sulfuric iacid ester" oi Ilaurwl alco- 1. A process which comprises reacting isobuqhol. V. tane with diisobutylene under alkylation 1 6: .1118; Aprocesawhichcomprises-reacting isoparetion conditions in the presence oi-sulfuric acid aflin withpleilniundenralkylationreaction'conof alkylating concentratiom said acid containditionsln the presenceiofzsulturic'acld 01 a1kylat-'- ing analkylation-promotihg agentselectedirom 35 ing-iconcentration, saidacid containing an N- the group cf wetting agents consistingwoif high acyl taurlneipresent in promotional sam'ounts; molecular weight v-N-acyl taurines, end sulfuric s9iiA process aszin ciaim anwhereinthe-sulturi acid esterslot high mo1ec'ulsr. weight liphatic acid containsprcmotionai:amountsoi monohydrlc A cmwr n ms.

2 Arr whi b fii' se i0 aflln with monooicnnu dcr sikyl ti mrcaction 

